Portable information apparatuses, such as notebook personal computers, are often coupled with networks, such as the Internet, via wireless local area networks (LANs) since having their portability.
FIG. 4 is a perspective view of conventional notebook personal computers 1011 and 2011. A whip antenna 1015 is a vertical antenna for a wireless communication of a standard of a digital portable phone, and enables the notebook personal computers to receive the same service as internet-connecting services provided for portable phones. Each of notebook personal computers 1011 and 2011 include display unit 1013 and main body 1012. Hinge unit 1014 couples display unit 1013 with main body 1012 rotatably with respect to main body 1012. Notebook personal computers 1011 and 2011 are folded at hinge unit 1014 while they are not used or are carried. A signal line, a power supply line, and a ground line are provided between main body 1012 and display unit 1013 through hinge unit 1014. A wire, such as flexible wire, having durability against bending is suitable to these lines, but a thick wire which does not have durability against bending is not suitable to them.
FIG. 5A is a schematic diagram of notebook personal computer 1011. Wireless module 1016 receives high frequency signals at antenna 1015, and demodulates the signals to provide digital signals. Wireless module 1016 modulates signals with digital signals to convert the digital signals into high frequency signals which meet a portable phone network standard, and sends the high frequency signals from antenna 1015. Controller 1018 generates or processes the digital signals, and controls operations, such as the switching of sending/receiving of wireless module 1016, of notebook personal computer 1011. Wireless module 1016 and controller 1018 are located in main body 1012 of notebook personal computers 1011. Antenna 1015 mounted to display unit 1013 is coupled with wireless module 1016 via coaxial cable 1031 passing through hinge unit 1014. Coaxial cable 1031 transmits weak high frequency signals received to wireless module 1016, and transmits the high frequency signals generated by wireless module 1016 to antenna 1015.
Coaxial cable 1031, a cable having a small loss in high frequencies, generally includes a core wire, a braided copper wire surrounding the core wire, a polyethylene insulator insulating the core wire from the braided copper wire, and a vinyl cover surrounding the outer circumference of the braided copper wire. Coaxial cable 1031 is thicker and weaker in bending than an ordinary single wire, accordingly not being suitable to be drawn through hinge unit 1014 and arranged. Coaxial cable 1031 has a small loss. However, according to lengthening a distance between antenna 1015 and wireless module 1016, coaxial cable 1031 has the loss increasing, and is influenced easily by noises from surrounding circuits. Hinge unit 1014 may be made of metal as to provide strength. If a housing of personal computer 1011 is made of metal to provide the strength, an eddy current is generated on a surface of the housing by the high frequency signals transmitted in long coaxial cable 1031, thereby producing losses.
FIG. 5B is a schematic diagram of notebook personal computers 2011. Unlike notebook personal computers 1011 shown in FIG. 5A, in personal computers 2011, wireless module 2016 is located in display unit 1013. Wireless module 2016 and controller 1018 are coupled with each other with plural signal lines 2032 for transmitting digital signals having plural bits or control signals. Furthermore, signal lines 2032 pass through hinge unit 1014. The number of bits of the digital signals is large, and the number of signal lines 2032 becomes accordingly large. Thus, signal lines 2032 may not pass easily through hinge unit 1014 having a predetermined size. In addition, signal lines 2032 are often bound together and arranged within the predetermined size, thereby allowing signals transmitted therein to be interfered with each other.
As shown in FIG. 5B, antenna 1015 and a high frequency circuit are arranged in the upper portion of display unit 1013 for preventing human bodies from influences of the device emitting electromagnetic waves even when the computer is used not only on a desk but also on a lap. In regard to devices emitting electromagnetic waves to human bodies, according to the growth of the market of portable phones, a standard of electromagnetic waves permissible for human bodies has been determined as a specific absorption rate (SAR).